Just so i understand they shut the engine down about 2 hours from Hilo. I'm guessing( did not read the article yet) that Hilo was closer than turning back?
KLAX-PHNL is a 5hr 35min flight...so
"about" two hours out (one article I read on this said 90 mins out) would be much closer to PHTO, PHOG, or PHNL for that matter, then turning back to KLAX. It would have been about 3 1/2 to 4 hours back. The aircraft on the flight was a B767-300, an ETOPS-120 aircraft.
Just some info on ETOPS and LROPS:
Twin engine aircraft that fly over water have to be ETOPS (Extended-range Twin-engine Operational Performance Standards) certified. Now there are different degrees of ETOPS:
From WIKI:
"In 1953, the US Federal Aviation Administration, having recognized piston engine limitations, introduced the "60-minute rule" for 2-engine aircraft. This rule stated that the flight path of twin-engined aircraft should not be farther than 60 minutes of flying time from an adequate airport. This forced these aircraft, on certain routes, to fly a dogleg path to stay within regulations; they were totally excluded from certain routes due to lack of en-route airports. The "60-minute rule" was also called the "60-minute diversion period." The totally excluded area was called the "exclusion zone."" The 60 minute rule would later become EROPS (extended range operations) until the mid-1980s, then change again to ETOPS.
...here are the degrees...
ETOPS: This means that the aircraft should be able to fly with full load and just one engine for 1 hour on one engine.
ETOPS-75: This means that the aircraft should be able to fly with full load and just one engine for 75 minutes on one engine.
ETOPS-90: This means that the aircraft should be able to fly with full load and just one engine for 90 minutes on one engine.
ETOPS-120: This means that the aircraft should be able to fly with full load and just one engine for 2 hours on one engine.
ETOPS-180: This means that the aircraft should be able to fly with full load and just one engine for 3 hours on one engine.
Airbus A300, A310, A320, A330 and A350 families, and the Boeing 737, 757, 767, 777 and 787 and Tupolev Tu-204 are all ETOPS Certifiable. ETOPS ratings are based on airframe/powerplant reliability.
The FAA gave the first ETOPS rating in May 1985 to TWA for the B767 service between St. Louis and Frankfurt, allowing TWA to fly its aircraft up to 90 minutes away from the nearest airfield: this was later extended to 120 minutes after a federal evaluation of the airline's operating procedures.
Rules governing 3 or 4 engine aircraft (B727, DC-8 DC-10, MD-11, L-1011, B707, B747, A340, A380) are covered under LROPS (Long Range Operational Performance Standards) rules.